CONSTANT = find_system(bdroot,'FindAll','on','BlockType','Constant');
for i = 1: length(CONSTANT)
    value = get_param(CONSTANT(i),'Value');
    if strcmp(value, 'TRUE')
        set_param(CONSTANT(i),'Value','true');
    end
    if strcmp(value, 'FALSE')
        set_param(CONSTANT(i),'Value','false');
    end    
end